A current need is to be able to know the spectrum of the signals received by a receiver within a range of operating frequencies over which it can operate when it is installed on board a satellite.
The knowledge of the spectrum can allow noise interference to be detected and solutions for resisting noise interference to be implemented or the reception frequencies of several satellites to be optimized during an orbital position change.
One solution for tracing this spectrum consists in installing a spectrum analyzer on board the satellite. The spectrum analyzer has the drawback of being a unit of equipment which as such occupies a non-negligible volume on the satellite. However, one challenge is to limit as far as possible the number of units of equipment installed on board satellites. Furthermore, this unit of equipment is complex and costly.
Another solution consists in analyzing, in a ground station, the power of the signals sent back to this station by a repeater installed on board the satellite. The satellite repeater receives uplink signals, amplifies them and transmits downlink signals based on the amplified signals. This solution has the following drawback: the uplink signals which are amplified and re-transmitted are, for example, useful telecommunication signals emitted within predetermined frequency bands spaced out from one another. The signals are re-emitted within the same bands or within other frequency bands also spaced out from one another. The analysis on the ground does not allow the spectrum between these bands of frequency to be known. In other words, it is not possible to know the power spectrum of the signals received by the receiver over the entirety of the range of operating frequencies of the receiver.